Study on the separation mechanism of 1-phenyl-3-methyl-5-pyrazolone derivatives of aldoses in acid buffer by capillary zone electrophoresis

Abstract

Baseline separation was achieved for 1-phenyl-3-methyl-5-pyrazolone (PMP) derivatives of six usual aldoses by capillary zone electrophoresis (CZE) using acid buffer (pH 2.5). The result showed that the migration times of mannose and rhamnose were much longer than those of the other four aldoses, though the molecular weights of the two monosaccharides were parallel to the others. This phenomenon is due to the intramolecular ring formation in PMP-aldoses, which impairs the conjugate in the pyrazolone ring, and further increases the alkalinity and positive charge of PMP-aldoses in acidic ambience. The aldose having 2,3-trans disposition will be favorable for ring formation and has more positive charge than that of the aldose having 2,3-cis disposition.